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/* pic.c -- Simulation of OpenRISC 1000 programmable interrupt controller

   Copyright (C) 1999 Damjan Lampret, lampret@opencores.org

This file is part of OpenRISC 1000 Architectural Simulator.

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

/* This is functional simulation of OpenRISC 1000 architectural

   programmable interrupt controller.

*/

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include "config.h"

#ifdef HAVE_INTTYPES_H

#include <inttypes.h>

#endif

#include "port.h"

#include "arch.h"

#include "abstract.h"

#include "pic.h"

#include "spr_defs.h"

#include "except.h"

#include "sprs.h"

#include "sched.h"

#include "debug.h"

extern int cont_run;

DEFAULT_DEBUG_CHANNEL(pic);

/* Reset. It initializes PIC registers. */

void pic_reset()

{

  PRINTF("Resetting PIC.\n");

  mtspr(SPR_PICMR, 0);

  mtspr(SPR_PICPR, 0);

  mtspr(SPR_PICSR, 0);

}

/* Handles the reporting of an interrupt if it had to be delayed */

void pic_clock(void *dat)

{

  /* Don't do anything if interrupts not currently enabled */

  if(testsprbits (SPR_SR, SPR_SR_IEE))

    except_handle(EXCEPT_INT, mfspr(SPR_EEAR_BASE));

  else

    SCHED_ADD(pic_clock, NULL, 1);

}

/* WARNING: Don't eaven try and call this function *during* a simulated

 * instruction!! (as in during a read_mem or write_mem callback).  except_handle

 * assumes that this is the case, it breaks otherwise. */

/* Asserts interrupt to the PIC. */

void report_interrupt(int line)

{

  setsprbits(SPR_PMR, SPR_PMR_DME, 0); /* Disable doze mode */

  setsprbits(SPR_PMR, SPR_PMR_SME, 0); /* Disable sleep mode */

  TRACE("Asserting interrupt %d (%s).\n", line, getsprbit(SPR_PICMR, line) ? "Unmasked" : "Masked");

  if (getsprbit(SPR_PICMR, line) || line < 2) {

    setsprbit(SPR_PICSR, line, 1);

    /* Don't do anything if interrupts not currently enabled */

    if (testsprbits (SPR_SR, SPR_SR_IEE)) {

      except_handle(EXCEPT_INT, mfspr(SPR_EEAR_BASE));

      TRACE("Delivering interrupt on cycle %lli\n", runtime.sim.cycles);

    } else

      /* Interrupts not currently enabled, retry next clock cycle */

      SCHED_ADD(pic_clock, NULL, 1);

  }

}